A spray device of this type comprises a can which is closed by a valve body including a small valve member held in a closed position at rest by a spring. When the valve rod is pushed into the can of the spray device, its contents escapes. Depending on requirements, when continuous pressure is exerted on the valve rod, a permanent aerosol jet or merely a single dose is released. The invention is applicable to all kinds of valve, including pumps. The requirement is for such spray devices to be presented in packaging which serves not only to facilitate subsequent use thereof, but which also serves initially to prove that the device has not been used by anybody else.
In general, the problem of making such spray devices easy to use and the problem of ensuring that they have not been used before are solved in different ways. Thus, pushers having a wide variety of shapes are fitted over the valve body and engage the valve rod internally, e.g. for the purpose of pushing the valve rod merely by applying index-finger pressure. Simultaneously, metal or plastic seals may be disposed around the spray orifice. Although it would not be impossible to design a seal for a non-removeable pusher, the corresponding product would not necessarily be easy to prepare. This drawback is particularly burdensome for a pharmaceutical laboratory which seeks to package spray devices easily for commercialization purposes once they have been filled with medical preparations.